This application is a continuation of Ser. No. 514,389 filed Apr. 25, 1990, now abandoned.
The present invention relates to object detection systems in general and, more particularly, to an object detection system and method for detecting the presence of objects in the path of a movable vehicle.
Various systems have been proposed in the prior art to warn drivers of the presence of an object in the path of a movable vehicle. Typically, such warning systems provide a suitable warning signal, either audible or visual or both, upon detecting the presence of an object in the path of a moving vehicle. System actuation occurs when the driver engages reverse gear to back up the vehicle. Representative examples of such systems can be found in U.S. Pat. Nos. 3,360,775 (transmitter and transducer receivers located in pairs at the corners of a vehicle); 4,278,962 (rotating transmitter and rotating receiver); 4,667,195 (corner located transmitter with adjacent receiver); 4,623,032 (transmitter located at each corner with a centrally located receiver); 4,551,722 (closely spaced transmit/receive transducers with a fixed reflector for calibration purposes); and 4,490,716 (an array of transmitters).
The prior art that is represented by the patents listed above does not provide an inexpensive, relatively simple and accurate system for producing a warning signal of the presence of an object in the path of a movable vehicle.
It is accordingly a general object of the present invention to provide an improved object detection system for movable vehicles.
It is a specific object of the invention to provide an object detection system for movable vehicles that utilizes a single stationary transmitter and a single stationary receiver.
It is a further object of the invention to provide an object detection system for movable vehicles utilizing a single transmitter and single receiver that are relatively widely spaced apart with respect to the width of the vehicle.
It is a still further object of the invention to provide an object detection system for movable vehicles utilizing a single transmitter and receiver with the transmitter and receivers spaced apart by a distance such that the transmitter and receiver are the foci of an elliptical path that constitutes the loci of all points of signal reflection having the same total transit time of signal from the transmitter to the reflecting object and back to the receiver.
It is still another object of the invention to provide an object detection system for movable vehicles in which the elliptical path of the loci of the closest detectable objects encompasses substantially the entire end portion of the movable vehicle.
It is a feature of the invention that the system can be assembled from relatively inexpensive, readily available electronic components.
It is another feature of the invention that the system can be mounted on a variety of different. types of vehicles without requiring significant alteration of the structure of the vehicle.